Rivet set retaining collar



J. PENQZLASE RIVET SET RETAINING COLLAR Filed Oct. 14, 1935 April 19, 1938.

Patented Apr. 19, 1938 UNITED STAT mvn'r SET RETAINING COLLAR Joseph Penglase,

Rogers City, Mich.

Application October 14, 1935, Serial No. 44,979

3 Claims.

The invention relates to riveting hammers and similar machines having a reciprocating working tool. More particularly the invention concerns improved means for retaining the working tool within the machine and which will not interfere with the free movement of said tool.

Many accidents have occurred as a result of careless or intentional discharge of the rivet set of air hammers. This led to the development of hammer but the device has the disadvantage that it merely holds the rivet set in position and does not offer sufficient resistance to dislodgment of the rivet set, especially after the clip has become worn by the severe usage to which it is subjected.

The present invention has for its object to provide a metal collar that may be readily applied to air hanuners and which when in place will.

prevent the rivet set and piston from being discharged either intentionally or carelessly by the operator. The collar requires the provision of a groove on the outside of the hammer cylinder near its outer end and by integral locking means formed on the collar and independent locking screws the collar is securely held in place although its presence will not interfere with the free movement of the rivet set.

Another object is to provide a rivet set retaining collar that can be readily applied and removed and which will consist of relatively few parts that may be securely locked in assembled relation.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation as will be more fully described and particularly pointed out in the specification, drawing and claims appended hereto.

In the drawing which illustrates an embodiment of the invention and wherein like reference characters are used to designate like parts Figure 1 is a longitudinal sectional view taken through the cylinder end of a riveting hammer 45 and showing the improved retaining collar in place;

Figure 2 is an elevational view of the retaining collar with the parts in separated position; Figure 3 is an elevational View of a modified 50 form of retaining collar;

Figure 4 is an end view of the same; and

Figure 5 is an elevational view showing the retaining collar of Figure 2 with the interlocking parts thereof retained in assembled relation by a locking screw.

a spring clip for holding the set within the air (on. are-19.6)

The present invention is illustrated in' connec' tion with an air hammer of conventional design and which consists of a hammer cylinder ill provided with a longitudinal bore H within which is located the hammer piston E2. The rivet set designated in its entirety by numeral 53 has the shank portion thereof projecting within the end of the hammer cylinder where contact between the same and the piston I2 may take place. The outer end of the hammer cylinder H3 is provided with a relatively wide groove it for holding the retaining collar designated generally by numeral [5 in place on the cylinder. The rivet set is formed with an annular retaining flange it which cooperates with the end of the hammer cylinder to limit the extent to which the rivet set projects within said cylinder. Said flange is also adapted to engage with the outer end of the retaining collar and thus movement of the rivet set outwardly is limited.

As shown in Figure 2 the collar consists essentially of an upper and lower section ll and I8 which when assembled produces a collar of frusto-conical shape, which gradually tapers from the maximum diameter at its left hand end to its minimum diameter at the right hand end. The upper section I! is formed with oppositely disposed depending portions 2|], which portions are of substantially dove-tail shape, having a bevel 2! at one end thereof and a semicircular screw threaded recess 22 at the opposite end. The lower section I8 is formed with oppositely disposed recesses 23 also of substantially dove-tail shape and designed to receive the depending portions 20. One end of each recess. is provided with a semi-cylindrical screw threaded recess 24 which in conjunction with the recess 22 of the upper portion forms a threaded opening for receiving a locking screw 25 shown in dotted lines in Figure 1. When the upper and lower sections of the collar are assembled by locating the depending portions 20 within the recess 22 the sections will be held together by the dove-tail joint and disassembly thereof is made impossible by threading the screw 25 in each opening formed by the semi-cylindrical recesses 22 and 24.

As shown in Figure 1, the left end of the collar is formed with an inwardly directed annular flange or lip portion 26 and a similar flange 21 is formed on the opposite end of the collar, which represents the forward end when the device is in place on the hammer cylinder.

With the sections of the collar assembled and in place on the end of a rivet hammer, as shown in Figure 1, it will be observed that the flange 26 encircles the hammer cylinder, being located within groove l4 formed in the end of the cylinder. This securely locks the collar to the hammer cylinder and removal of the collar therefrom can only be efiected by first removing the screws 25 and then separating the sections l1 and I8 of the collar. The inwardly directed flange 21 encircles the rivet set and provides a stop for the retaining flange It which in effect limits further outward movement of the rivet set.

The improved retaining collar of the invention can be readily applied to any fluid pressure implement of the type having a reciprocating working tool and only requires a groove in the lower end of said implement for holding the collar thereon. The collar does not increase the weight of the tool to any great extent but on the. other hand provides the strength required to make it impossible to dislodge the working tool from the device. Although the tool is effectively retained so that its discharge either intentionally or by careless and inexperienced workmen is impossible, nevertheless the collar does not interfere with the operations of the working tool and further the collar can be readily removed in case it is desired to remove the tool or to replace a worn piston.

The modified form of retaining collar shown in Figure 3 is similar in many respects to the preferred form described in connection with Figures 1 and 2. The collar comprises three sections, a lower section 28 and two upper sections 29 and 30. The lower section is semi-circular in contour and is substantially identical with section I8 of the preferred form, while the two upper sections when assembled form a unit substantially similar to section ll.

Constructing the upper section of the collar in two parts greatly facilitates assembly of the same but requires the addition of spring clips 3| for holding the various sections in assembled relation. In this connection, it is preferred to em ploy two spring clips 3|, each clip fitting within a groove 32 formed in the outer periphery of the collar and located at the respective ends of the collar. It may be noted with respect to this modified form that the openings for the screws 25 have been omitted. However, it is within the invention to provide such openings and in fact for certain uses it may be necessary to employ screws for the interlocking sections. The addition of spring clips, or at least one clip, to the collar of Figure 1 is also a possibility as the clips could be located so as to cover the screws 25 and thus efiectively prevent the screws from working loose.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawing, as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

l. A rivet set retaining collar for an air hammer, said collar comprising two semi-circular sections and having an inturned flange at one end fitting Within a groove formed on said hammer, the other end of the collar providing a stop limiting outward movement of the rivet set, said sections having locking portions formed integral with the sections, and independent locking means for the sections inserted at a point of juncture between the sections.

2. A rivet set retaining collar for an air hammer, said collar comprising two semi-circular sections and having an inturned flange at one end fitting within a groove formed on said hammer, the other end of the collar providing a stop limiting outward movement of the rivet set, said sections having depending portions and recesses, respectively, adapted to interlock when the sections are assembled, and independent locking means inserted at a point of juncture between the sections and lying partially within each section! 3. A rivet set retaining collar for an air ham' mer, said collar comprising two semi-circular sections and having an inturned flange at one end fitting within a groove formed on said hammer, the other end of the collar providing a stop limiting outward movement of the rivet set, one section having depending portions, the other section having recesses adapted to receive the depending portions when assembled and to interlock the sections, and independent locking means for the sections inserted at a point of juncture between the sections and lying partially within each section.

JOSEPH PENGLASE. 

